Device in offset printing presses for controlling the supply of dampening liquid to dampening equipment of the presses

ABSTRACT

Offset printing press having a main motor and dampening equipment includes a device for automatically controlling a supply of dampening liquid to the dampening equipment. The device includes an adjusting motor which has a rotary shaft and which is connected to the main motor for controlling the rotary speed thereof, a control cam secured to the shaft, as for example, illustrated in U.S. Pat. No. 2,561,837, and control member means operatively engageable by the control cam for determining the amount of liquid supplied from a source thereof to the dampening equipment.

United States Patent Heidt 1 1 Sept. 17, 1974 DEVICE IN OFFSET PRINTING PRESSES 1,631,752 6/1927 Merrill 318/361 x FOR CQNTROLLING THE SUPPLY OF goilsgeau et a1. 1016311624);

v v 0 Cl' DAMPENING LIQUID To DAMPENING 2,561,837 7/1951 Baumann et a1 318/361 X EQUIPMENT OF THE PRESSES 2,971,461 2/1961 Bradford et a1 101/426 75 Inventor: Heinrich Heidt, Neckarsteinach, 3,234,871 2/1966 Ostvyald 101/142 Germany 3,601,644 8/1971 Perlmo 1 1 310/241 3,693,063 9/1972 Sillano 318/361 [73] Assignee: Heidelberger Druckmaschinen Aktiengesellschafi, Heidelberg, Primary Examiner-l Reed Fisher Germany Attorney, Agent, or Firm-Herbert L. Lerner [22] Filed: Nov. 21, 1972 21 Appl. No.: 308,342 [57] ABSTRACT Offset printing press having a main motor and dampening equipment includes a device for automatically [30] Foreign Apphcatmn Pnonty Data controlling a supply of dampening liquid to the damp- Nov. 22, 1971 Germany 2157778 ening equipmem The device includes an adjusting motor which has a rotary shaft and which is connected [52] US. Cl. 101/148, l0l/366 to the main motor for Controlling the rotary Speed [51] II. Cl B411 25/12, 1341f 7/32 thereof, a Control Cam Secured to the Shaft as for [58] Fleld of Search 101/366, 147, 148, 350, ample, illustrated in U S NO. 2 5 1 37 and 101/364; 310/24]; 318/361 trol member means operatively engageable by the control cam for determining the amount of liquid sup- [56] References C'ted plied from a source thereof to the dampening equip- UNITED STATES PATENTS m 1,279,360 9/1918 Kirthals-Aotes 318/361 1,505,929 8/1924 Prescott 318/361 X 5 Glam, 1 Drawmg DEVICE IN OFFSET PRINTING PRESSES FOR CONTROLLING THE SUPPLY DAMPENING LIQUID TO DAMPENING EQUIPMENT OF THE PRESSES SPECIFICATION The invention relates to offset printing presses having a device for controlling automatically the supply of dampening liquid to dampening equipment of the presses, and more particularly to such offset printing presses which are provided with an adjusting motor for controlling the rotary speed of the main shaft of the printing presses, for example, by adjusting the collector brushes of the main shaft.

As is generally known, difficulty arises in supplying a correctly metered quantity of dampening liquid in all of the speed ranges of the printing platen in offset printing presses. It should be noted in this regard that the liquid requirement is ordinarily not proportional to the change in printing speed. Too small a supply of liquid can, however, produce tones while an excess of liquid supplied to the printing platen causes dilution of the ink and leaves behind the undesired appearance of water streaks.

It is accordingly an object of the invention to provide a device which will ensure the supply of accurately metered liquid through the dampening equipment to the printing platen of an offset printing press of whatever type at any printing speed thereof.

It is another object of the invention to provide such device which will effectively control the dampening liquid supply by relatively simple and inexpensive mechanically operating controls rather than by heretofore known costly electronic systems that are subject to frequent breakdown.

With the foregoing and other objects in view, there is provided in accordance with the invention, in an offset printing press having a main motor and dampening equipment, a device for automatically controlling a supply of dampening liquid to the dampening equipment, comprising an adjusting motor connected to the main motor for controlling the rotary speed thereof, said adjusting motor having a rotary shaft, a control cam secured to the shaft, and control member means operatively engageable by the control cam for determining the amount of liquid supplied from a source thereof to the dampening equipment.

The control cam is provided with a cam surface based upon empirically determined dimensions which will ensure that the printing platens of offset printing presses of the same type will always receive accurately metered moisture at all printing speed of the presses. The cam surface will have a curvature empirically determined by setting the printing press at different speeds with the valve opening to permit desired flow of moisture at each speed correlated to the point on the cam surface such that the cam surface thus empirically determined will always effect the same valve opening for a given speed.

In accordance with another feature of the invention, when the dampening equipment is of the conventional syphonless type; the control cam actuates a control valve through a control member with which the control cam is in engagement.

In accordance with a further feature of the invention, when the dampening equipment is of the conventional syphon type and is provided with immersion rollers having a rotary speed control, the control cam acts upon the rotary speed control through a control member with which the control cam is in engagement.

Other features which are considered as characteristic for the invention are set forth in the appended claims.

Although the invention is illustrated and described herein as embodied in device in offset printing presses for controlling the supply of dampening liquid to dampening equipment of the presses, it is nevertheless not intended to be limited to the details shown since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.

The construction and method of operation of the invention, however, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying single figure of the DRAWING which is a schematic view of a device for controlling the supply of dampening liquid to the dampening equipment of an offset printing press constructed in accordance with the invention.

Referring now to the drawing, there is shown diagrammatically therein the collector l of a main motor 2 of an offset printing press which is not otherwise illustrated. The collector 1 is provided with collector brushes 3 that are adjustable in accordance with the desired rotary speed of the main motor 2. The adjustment of the collector brushes 3 is effected by a brushadjusting ring gear 4 which is driven by a pinion 5 that is in meshing engagement therewith. The pinion 5 is secured to one free end of the shaft 6, a control cam 8 is mounted and is in actuating engagement with a cam follower or roller 9 which is rotatably carried by a linkage 10 through which the cam follower roller 9 is formlockingly connected in a conventional manner with the non-illustrated closure member of a control valve diagrammatically represented by the box 11. The control valve 11 controls the supply of liquid to dampening equipment 12 of the offset printing press.

If the rotary speed adjusting motor 7 is adjusted to another printing speed than that set at in the figure, then, through the pinion 5 the adjusting motor 7, turns the brush-adjusting ring gear 4 and, accordingly, the collector brushes 3, whereupon the main motor 2 assumes the desired new rotary speed. Simultaneously, due to the rotation of the pinion, the control cam 8 has been turned and has assumed a new position. Because of the construction of the control cam 8 which is empirically arrived at by a man of ordinary skill in the art, the control valve 4 can be opened so wide that optimal dampening of the printing platen or platens of the press is effected for the newly adjusted printing speed.

In another non-illustrated embodiment of the invention, the control cam 8 is mounted directly on the shaft of the control member which adjusts the rotary speed adjusting motor 7 to the desired rotary speed.

I claim:

1. In an offset printing press having a main motor adapted to rotate the press at different speeds and dampening equipment for supplying dampening liquid to the press, the combination therewith of a device for automatically controlling a predetermined supply of dampening liquid to the dampening equipment, in accordance with the press speed, comprising an adjusting motor connected to the main motor for controlling the rotary speed thereof, said adjusting motor having a rotary shaft, a source of dampening liquid for supplying liquid to said dampening equipment, control member means for regulating the flow of dampening liquid from said source to said dampening equipment, a control cam secured to said shaft of said adjusting motor, said control member means operatively engageable by said control cam to vary the amount of liquid supplied from said source to the dampening equipment in accordance with the press speed, said control cam having a curved surface to activate said control member means to supply predetermined amounts of liquid at different press speeds.

2. Offset printing machine according to claim 1 wherein the main motor is provided with collector brushes, said adjusting motor being connected to said collector brushes for varying the position of said brushes.

3. Offset printing machine according to claim 1, wherein said control member means comprises a control member and said control valve operatively connected to said control member, said control member being engageable by said control cam so as to actuate said control valve to control flow of liquid therethrough.

4. Offset printing machine according to claim 1, wherein the dampening equipment includes an immersion roller and rotary speed control therefor, said control member means comprising a control member engageable by said control cam and operatively con nected to the rotary speed control for the immersion roller.

5. A method of automatically controlling a predetermined supply of dampening liquid to dampening equipment in accordance with press speed of an offset printing press having a main motor adapted to rotate the press at different speeds and dampening equipment for supplying dampening liquid to the press, which comprises supplying liquid to said dampening equipment from a source of dampening liquid, regulating the flow of dampening liquid from said source to said dampening equipment by means of a control member, varying the amount of liquid supplied from said source to said dampening equipment by a control cam having a curved surface to activate said control member to supply predetermined amounts of liquid at different press speeds, and simultaneously moving said control cam with change of press speed to effect flow of predetermined amount of liquid at each press speed. 

1. In an offset printing press having a main motor adapted to rotate the press at different speeds and dampening equipment for supplying dampening liquid to the press, the combination therewith of a device for automatically controlling a predetermined supply of dampening liquid to the dampening equipment, in accordance with the press speed, comprising an adjusting moTor connected to the main motor for controlling the rotary speed thereof, said adjusting motor having a rotary shaft, a source of dampening liquid for supplying liquid to said dampening equipment, control member means for regulating the flow of dampening liquid from said source to said dampening equipment, a control cam secured to said shaft of said adjusting motor, said control member means operatively engageable by said control cam to vary the amount of liquid supplied from said source to the dampening equipment in accordance with the press speed, said control cam having a curved surface to activate said control member means to supply predetermined amounts of liquid at different press speeds.
 2. Offset printing machine according to claim 1 wherein the main motor is provided with collector brushes, said adjusting motor being connected to said collector brushes for varying the position of said brushes.
 3. Offset printing machine according to claim 1, wherein said control member means comprises a control member and said control valve operatively connected to said control member, said control member being engageable by said control cam so as to actuate said control valve to control flow of liquid therethrough.
 4. Offset printing machine according to claim 1, wherein the dampening equipment includes an immersion roller and rotary speed control therefor, said control member means comprising a control member engageable by said control cam and operatively connected to the rotary speed control for the immersion roller.
 5. A method of automatically controlling a predetermined supply of dampening liquid to dampening equipment in accordance with press speed of an offset printing press having a main motor adapted to rotate the press at different speeds and dampening equipment for supplying dampening liquid to the press, which comprises supplying liquid to said dampening equipment from a source of dampening liquid, regulating the flow of dampening liquid from said source to said dampening equipment by means of a control member, varying the amount of liquid supplied from said source to said dampening equipment by a control cam having a curved surface to activate said control member to supply predetermined amounts of liquid at different press speeds, and simultaneously moving said control cam with change of press speed to effect flow of predetermined amount of liquid at each press speed. 